PRIOR CONCURRENT THERAPY: Biologic therapy: At least 4 weeks since prior immunotherapy and recovered Chemotherapy: At least 4 weeks since prior cytotoxic chemotherapy and recovered Endocrine therapy: At least 4 weeks since prior hormonal therapy and recovered No concurrent corticosteroids Radiotherapy: At least 4 weeks since prior radiotherapy and recovered Surgery: At least 4 weeks since prior surgery and recovered No prior splenectomy